1. Field of the Invention
The present invention relates to a zero-insertion-force (hereafter ZIF) connector.
2. Description of Related Art
Central processing unit (CPU) sockets are widely used in personal computer (PC) systems to electrically connect integrated circuit (IC) chips with printed circuit boards (PCBs), pins in the IC chips increase accordingly. To mount a CPU socket with so many pins to a connector needs a very large inserting force. Such a large inserting force will cause a difficulty to mount/dismount the CPU socket or contacts of the CPU sockets if there is a deviation of positional precision of the pins or the contacts. Thus, a ZIF connector is developed, when it is at an open position the pins of the IC chip can be freely inserted into the CPU socket without engagement with the contacts, when it is at an closed position the pins of the IC chip can engage with the contacts so that an electrical connection is achieved between the IC chip and the PCB. The ZIF connector is motivated by an actuator thereof to a closed position thereby moving the pins to engage with the contacts.
The conventional ZIF connector comprises a plastic base, a plastic cover slidably mounted onto the base, a plurality of electrical contacts received in the base, and a metallic actuator. The plastic cover is actuated to slide on the plastic base by rotating of the metallic actuator, thereby causing pins of integrated circuit chip mounted on the cover to engage/disengage with the contacts in the plastic base. The plastic cover defines a circular-shaped recess in one side thereof. Two stop walls are formed in the inner surface of the circular-shaped recess. The metallic actuator comprises a lateral protruding protrusion. The protrusion of the actuator is rotatable in the circular-shaped recess. Rotation of the actuator causes the plastic cover to slide on the plastic base, mating or unmating the pins of the integrated circuit chip on the cover with the contacts of the plastic base.
However, when the protrusion of the actuator rotates between two limit positions defined by the stop walls and abuts against one of the stop walls, the large force exerted by the protrusion may tend to damage the stop walls during operation because the metallic material has a higher strength than the plastic material, thereby causing malfunction of the ZIF connector. Further, the plastic cover tends to be worn out by the rotation of the metallic actuator therein, resulting in a shortened life thereof, and in turn a shortened life of the connector. The disadvantages as above of this type of connector is existed in U.S. Pat. No. 6,146,178, which can not escape from the risk of damaging the plastic cover of the connector.
Hence, an improved ZIF connector is desired to overcome the disadvantages and problems of the prior art.